The main difference between low molecular dextran and medium molecular dextran is the difference in molecular weight. Both are used in clinical treatment to resuscitate shock, replenish blood volume and expand blood volume. Low-molecular dextran, which also has anticoagulant and depolymerizing effects, can be used in patients with thromboembolic diseases. When resuscitating shock, mainly to supplement hypertonic colloid, can be applied medium molecular dextrose, the first administration should not exceed 2000ml, because these drugs are mainly metabolized by the kidneys, the acute phase is also easy to induce renal insufficiency, and long time medication, should also be regularly reviewed liver function as well as changes in renal function. Pay attention to the monitoring of urine volume to prevent the occurrence of related adverse drug reactions.